“MySQL server has gone away” with Ruby on Rails

Question

After our Ruby on Rails application has run for a while, it starts throwing 500s with \"MySQL server has gone away\". Often this happens overnight. It\'s started doing this

Answer 1

Something else to check is Unicorn config is correct. See before_fork and after_fork handling of ActiveRecord connection here: https://gist.github.com/nebiros/2776085#file-unicorn-rb